Simplify deposit_event declaration in decl_module (#3506)

* simplify module deposit_event declaration

* fix

* bump version

* fix

* fix test

* fix doc

substrate/srml/sudo/src/lib.rs

@@ -106,7 +106,7 @@ pub trait Trait: system::Trait {
 decl_module! {
 	// Simple declaration of the `Module` type. Lets the macro know what it's working on.
 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
-		fn deposit_event<T>() = default;
+		fn deposit_event() = default;
 
 		/// Authenticates the sudo key and dispatches a function call with `Root` origin.
 		///